The present invention relates to removable data storage media and, more particularly, to techniques for ensuring the integrity of data stored on such media.
Removable data storage media are widely used to store vast amounts of information. Some removable media are used primarily for portability. Magnetic diskettes such as 120 MB Imation Superdisk(trademark) media, for example, permit users to transport relatively large amounts of data between computers with convenience and security. Magnetic and optical tape are used primarily for inexpensive backup of huge volumes of data, both for desktop and data center applications. Other removable media such as optical, magneto-optic, and phase-change disks blend the benefits of portability, increased storage volume, and cost savings, and find a number of different storage applications.
As new technology yields greater data storage densities, the storage volumes offered by removable media similarly increase. With increased volumes, the value of the data stored on an individual diskette, disk, or tape cartridge ramps upward. Consequently, damage to a single storage medium becomes a greater concern. In the case of inoperability of an individual diskette, disk, or tape cartridge, large amounts of valuable data can be lost or corrupted. Data loss or corruption can result in the loss of productivity, time, and money. Therefore, data integrity is a paramount concern.
The present invention is directed to a data storage device that has a shock indicator disposed within its housing. The present invention is also directed to a data storage drive capable of interfacing with a data storage device to determine whether the device has been subjected to physical shock. In addition, the present invention is directed to methods of protecting data that is saved on a data storage device by detecting whether the device has been subjected to physical shock.
The ability to detect whether a data storage device has been subjected to a shock load can be highly advantageous in ensuring data integrity. If a data storage device has been subjected to a shock load, data carried by the device can be lost or corrupted. Alternatively, the shock load can cause damage or physical shifting of components that compromises proper read/write operation. Consequently, attempts to perform read or write operations with the data storage device can result in lost or corrupted data.
With a shock indicator, a user can determine whether a data storage device has been subjected to shock, and choose to refrain from further read and write operations and submit the device to data recovery services to avoid the risk of data loss or corruption. Alternatively, a drive or library in which the data storage device is used may be equipped with a detection device that interfaces with the shock indicator to automatically ascertain whether the device has been subject to shock. The drive or library can be configured to disable further read and write operations, or notify a user of the shock condition.
The data storage device includes a data storage medium such as magnetic tape, magnetic disk, optical disk, optical tape, magneto-optic disk, phase change disk, or holographic tape, or any other type of storage media. In addition, the data storage device may have a housing that substantially encloses the data storage medium. A media access opening can be provided in the housing to permit access to the media by a drive.
Disposed within the housing of the data storage device may be a shock indicator that is capable of indicating whether the device has been subjected to a physical shock. In particular, the shock indicator can be made responsive to shock loads in excess of a predetermined threshold. In an exemplary embodiment, the data storage device is a data storage tape cartridge that incorporates an internal shock detector.
Upon receipt of a shock load of sufficient magnitude, the shock indicator may change state, e.g., visually or physically. The cartridge housing may have an aperture and the shock sense indicator may be disposed adjacent to the aperture. In some embodiments, this may facilitate visual detection of the state of the shock sense indicator by a user or by an optical detector within a drive. In this case, a window may be disposed in the aperture to facilitate visual detection of the shock sense indicator while preventing contamination of the cartridge interior. In other embodiments, the aperture may provide physical access to the indicator, e.g., by a switch within a drive that ascertains the physical state of the shock indicator.
In some embodiments, the shock sense indicator includes a detector pin. The detector pin may be disposed within the housing at a first position. However, once the device has been subjected to a physical shock over a threshold, the detector pin may be displaced from its first position to some second position. If the detector pin is not in its first position, the shock sense indicator may be said to be in a xe2x80x9cshocked state.xe2x80x9d In at least one embodiment, the fact that the shock sense indicator is in a shocked state may be visually detectable by a user, via an aperture or translucent window disposed on the housing. Alternatively, the displacement of the detector pin may be detected by a mechanism within the drive, such as switch or optical detector.
The data storage device may also comprise a baseplate. The baseplate may be contained within the housing, or mounted to a cover to form a portion of the housing. In either case, the baseplate may physically engage the shock sense indicator that is disposed within the device. In one embodiment, the shock sense indicator includes a detector pin that is attached to the base plate in a particular position. By attaching the detector pin to the base plate in a particular position, the shock sense indicator may be tuned to a particular shock threshold such that when the device experiences a physical shock over that threshold, the shock sense indicator goes into a shocked state. For example, the base plate may have a slit adjacent to the detector pin. In particular, the slit may define a xe2x80x9cspringboard-likexe2x80x9d member in the baseplate. The detector pin may be attached to the springboard. By setting the dimensions and mechanical properties of the springboard-like member, the shock sense indicator may be tuned so as to be responsive to a certain threshold of force.
A shock detector pin can be disposed adjacent to an aperture in the housing of the data storage device. A data storage drive may have a mechanism, such as a detector switch, that detects whether the shock sense indicator is in a shocked state. The detector switch can be arranged to mate with an aperture on the housing of the data storage device. For example, the data storage drive senses that the data storage device is in an unshocked state when the drive detector switch is able to protrude through the aperture of the data storage device. In this case, a detector pin may have a recess to facilitate mating with the drive detector switch. In a related embodiment, however, the data storage drive may sense that the data storage device is in a shocked state when the drive detector switch is able to protrude through the aperture of the data storage device.
To promote directional sensitivity and/or tune the indicator pin to desired shock thresholds, the detector pin may have an offset mass attached thereto. The presence of the offset mass may make the shock sense indicator more sensitive to physical shock along a particular axis. For instance, if an offset mass is attached perpendicularly to the detector pin, the shock sense indicator may become more sensitive to physical shock if the device is dropped on an axis parallel to the position of the detector pin.
The detector pin may be snap fit into a base plate, or alternatively the detector pin may snap fit into the housing. The detector pin may have a flange disposed on its end that engages either the baseplate or the housing. Moreover, the detector pin may be partially pressed into the baseplate or the housing. In another embodiment, the detector pin may be wedge fitted within the housing. Furthermore, in yet another embodiment, the detector pin may include a spring.
A retaining area may envelop the detector pin. In one embodiment, a physical shock over a threshold jars the detector pin loose, while the retaining area houses the loose pin so as to protect the other components of the data storage device from contact with the pin. In this embodiment, the loose pin housed in the retaining area may provide a user with an audible indication that the shock sense indicator is in a shocked state. For instance, if a user shook the device and heard the loose part rattling within the retaining area, he or she would know that the device had been subjected to physical shock.
In another embodiment, at least one visible shock sense indicator may be disposed within the housing along with one or more inspection apertures disposed adjacent to the shock sense indicator. When the device has been subjected to physical shock over a threshold, the shock sense indicator may visibly convey that information to a user. The inspection aperture may simply be a hole. However, the inspection window may alternatively be a transparent or translucent material disposed on the housing of the device or forming part of the device housing. Multiple shock sense indicators may be used, and may be oriented differently such that each is more sensitive to physical shock along a unique axis. A data storage drive may include an optical detector, such as a photodiode, that resolves whether the device has been subjected to shock based on a change in the optical state of the shock indicator, e.g., from light to dark or vice versa.
With either a visible or mechanical shock indicator, the data storage drive may be configured to either enable or disable operations based on the status of the indicator. For example, the data storage drive may be unable to perform any read/write operation on the data storage device if the shock sense indicator is in a shocked state. Alternatively, the data storage drive may activate a read only mode upon sensing that the shock sense indicator is in a shocked state.
Moreover, the data storage drive may store shock sense data on the data storage device if the shock sense indicator is in a shocked state. The shock sense data may include the date and time that the data storage drive first stored sense data on the data storage device. The data storage drive may sense the shock sense data and operate in accordance with the status of that data. For instance, if the shock sense data indicates that the data storage device has been subjected to shock, the data storage drive may operate in a read only mode. This capability may allow technicians to diagnose the cause of a potential failure condition of the device.
In one embodiment, the present invention provides a data storage device comprising a data storage medium, a housing that substantially encloses at least a portion of the data storage medium, and a shock sense indicator disposed within the housing.
In another embodiment, the present invention provides a data storage drive for manipulating data stored on a data storage device, the data storage drive comprising a mechanism that interfaces with the data storage device to determine whether the data storage device has been subjected to physical shock over a threshold.
In a further embodiment, the present invention provides a data storage device comprising a data storage medium for storing data, a housing that substantially encapsulates the data storage medium, and a detector pin within the housing disposed at a first position, wherein a physical shock over a threshold causes the detector pin to move from its first position.
In an added embodiment, the present invention provides a data storage device comprising a data storage medium for storing data, a housing that substantially encapsulates the data storage medium, at least one visible shock sense indicator disposed within the housing, and an inspection aperture formed on the housing adjacent to the at least one visible shock sense indicator.
In another embodiment, the present invention provides a method for protecting data stored on a data storage device comprising providing a shock sense indicator inside a data storage device, checking whether the shock sense indicator has been subjected to physical shock over a threshold, and disabling the ability to operate at least one operation on the data storage device if the shock sense indicator has been subjected to physical shock over a threshold.
In a further embodiment, the present invention provides a method for protecting data stored on a data storage device comprising providing a shock sense indicator inside a data storage device, checking whether the shock sense indicator has been subjected to physical shock over a threshold, saving the data stored on the data storage device to another data storage medium, and retiring the data storage device in the event the shock sense indicator has been subjected to physical shock over a threshold.
In an added embodiment, the present invention provides a method of protecting data stored on a data storage device comprising providing a shock sense indicator inside a data storage device, determining whether the shock sense indicator has been subjected to a physical shock over a threshold, and preserving the data stored on the data storage device if the shock sense indicator has been subjected to a physical shock over a threshold.
In another embodiment, the present invention provides a data storage system comprising a data storage device that includes a data storage medium, a housing that substantially encloses at least a portion of the data storage medium, a shock sense indicator disposed within the housing, and a data storage drive for manipulating data stored on a data storage device, the data storage drive comprising a mechanism that interfaces with the data storage device to determine whether the data storage device has been subjected to physical shock over a threshold. Other advantages, features, and embodiments of the present invention will become apparent from the following detailed description and claims.